E-commerce Order Fulfillment - Upstash Documentation

Introduction

This example demonstrates an automated e-commerce order fulfillment process using Upstash Workflow. The workflow takes an order, verifies the stock, processes the payment, and handles order dispatch and customer notifications.

Use Case

Our workflow will:

Receive an order request
Verify the availability of the items in stock
Process the payment
Initiate the dispatch of the order
Send confirmation and delivery notifications to the customer

Code Example

api/workflow/route.ts

import { serve } from "@upstash/workflow/nextjs"import {  createOrderId,  checkStockAvailability,  processPayment,  dispatchOrder,  sendOrderConfirmation,  sendDispatchNotification,} from "./utils"type OrderPayload = {  userId: string  items: { productId: string, quantity: number }[]}export const { POST } = serve<OrderPayload>(async (context) => {  const { userId, items } = context.requestPayload;  // Step 1: Create Order Id  const orderId = await context.run("create-order-id", async () => {    return await createOrderId(userId);  });  // Step 2: Verify stock availability  const stockAvailable = await context.run("check-stock", async () => {    return await checkStockAvailability(items);  });  if (!stockAvailable) {    console.warn("Some items are out of stock");    return;  };  // Step 3: Process payment  await context.run("process-payment", async () => {    return await processPayment(orderId)  })  // Step 4: Dispatch the order  await context.run("dispatch-order", async () => {    return await dispatchOrder(orderId, items)  })  // Step 5: Send order confirmation email  await context.run("send-confirmation", async () => {    return await sendOrderConfirmation(userId, orderId)  })  // Step 6: Send dispatch notification  await context.run("send-dispatch-notification", async () => {    return await sendDispatchNotification(userId, orderId)  })})

main.py

from fastapi import FastAPIfrom typing import List, TypedDictfrom upstash_workflow.fastapi import Servefrom upstash_workflow import AsyncWorkflowContextfrom utils import (    create_order_id,    check_stock_availability,    process_payment,    dispatch_order,    send_order_confirmation,    send_dispatch_notification,)app = FastAPI()serve = Serve(app)class OrderItem(TypedDict):    product_id: str    quantity: intclass OrderPayload(TypedDict):    user_id: str    items: List[OrderItem]@serve.post("/order-fulfillment")async def order_fulfillment(context: AsyncWorkflowContext[OrderPayload]) -> None:    # Get the order payload from the request    payload = context.request_payload    user_id = payload["user_id"]    items = payload["items"]    # Step 1: Create Order Id    async def _create_order_id():        return await create_order_id(user_id)    order_id: str = await context.run("create-order-id", _create_order_id)    # Step 2: Verify stock availability    async def _check_stock():        return await check_stock_availability(items)    stock_available: bool = await context.run("check-stock", _check_stock)    if not stock_available:        print("Some items are out of stock")        return    # Step 3: Process payment    async def _process_payment():        return await process_payment(order_id)    await context.run("process-payment", _process_payment)    # Step 4: Dispatch the order    async def _dispatch_order():        return await dispatch_order(order_id, items)    await context.run("dispatch-order", _dispatch_order)    # Step 5: Send order confirmation email    async def _send_confirmation():        return await send_order_confirmation(user_id, order_id)    await context.run("send-confirmation", _send_confirmation)    # Step 6: Send dispatch notification    async def _send_dispatch_notification():        return await send_dispatch_notification(user_id, order_id)    await context.run("send-dispatch-notification", _send_dispatch_notification)

Code Breakdown

1. Verifying Stock Availability

We start by creating an order id and verifying if the items in the order are available in stock. If not, we throw an error to halt the process:

api/workflow/route.ts

const orderId = await context.run("create-order-id", async () => {  return await createOrderId(userId);});const stockAvailable = await context.run("check-stock", async () => {  return await checkStockAvailability(items)})if (!stockAvailable) {  console.warn("Some items are out of stock")  return;}

main.py

async def _create_order_id():    return await create_order_id(user_id)order_id: str = await context.run("create-order-id", _create_order_id)async def _check_stock():    return await check_stock_availability(items)stock_available: bool = await context.run("check-stock", _check_stock)if not stock_available:    print("Some items are out of stock")    return

2. Processing Payment

Once the stock is verified, the workflow processes the payment for the order:

api/workflow/route.ts

await context.run("process-payment", async () => {  return await processPayment(orderId)})

main.py

async def _process_payment():    return await process_payment(order_id)await context.run("process-payment", _process_payment)

3. Dispatching the Order

After payment confirmation, we dispatch the order for delivery:

api/workflow/route.ts

await context.run("dispatch-order", async () => {  return await dispatchOrder(orderId, items)})

main.py

async def _dispatch_order():    return await dispatch_order(order_id, items)await context.run("dispatch-order", _dispatch_order)

4. Sending Confirmation and Notification Emails

Lastly, we send an order confirmation email to the customer and notify them when the order is dispatched:

api/workflow/route.ts

await context.run("send-confirmation", async () => {  return await sendOrderConfirmation(userId, orderId)})await context.run("send-dispatch-notification", async () => {  return await sendDispatchNotification(userId, orderId)})

main.py

async def _send_confirmation():    return await send_order_confirmation(user_id, order_id)await context.run("send-confirmation", _send_confirmation)async def _send_dispatch_notification():    return await send_dispatch_notification(user_id, order_id)await context.run("send-dispatch-notification", _send_dispatch_notification)

Key Features

Stock Verification: Ensures items are available in stock before processing the payment, avoiding issues with unavailable products.
Payment Processing: Handles payment securely and only proceeds to dispatch if successful.
Customer Notifications: Keeps the customer informed at each step of the order process, improving user experience.